Resveratrol Attenuates Copper-Induced Senescence by Improving Cellular Proteostasis

Figure 6

CuSO₄-induced accumulation of carbonylated and polyubiquitinated proteins is reduced by resveratrol, through lysosomal autophagy induction. (a) Protein carbonyl content and (b) polyubiquitinated (poly-Ub) proteins were evaluated in fibroblasts submitted to the indicated conditions by western blot. Representative blots are depicted and densitometric quantification was normalized by attributing the value 1 for control cells in the absence of resveratrol. Ponceau S staining was used as protein loading control. (c) Lysosomal autophagy was studied by the conversion of LC3-I to LC3-II, a critical step for autophagosome formation, and quantification of P62, an ubiquitin-binding protein that target Ub-substrates to autophagosomes. LC3-II/LC3-I ratio and P62 relative levels were evaluated upon densitometric quantification and plotted assuming that control cells without resveratrol present a value of 1. Data represent mean ± SEM of at least three independent experiments. ; ; ; and , for the comparisons between the indicated groups.

(a)

(b)

(c)